A Portuguese man-of-war is displayed at the end of forceps at the National Museum of Marine Science and Technology in Keelung on Tuesday last week.

Photo: Lu Hsien-hsiu, Taipei Times

With summer’s heat arriving, enjoying time on the beach and in the sea may be attractive, but beachgoers around Keelung should be on their guard after Portuguese men-of-war were sighted off different parts of the northern coast.

The Portuguese man-of-war is a jellyfish-like siphonophore. Though each appears to be a single individual, the Portuguese man-of-war is actually an entity made up of interconnecting colonial organisms with different functions.

The creature is best known for its venomous sting, which can leave long whip-like red welts on victims. The sting can also lead to an allergic reaction in certain individuals, sometimes leading to fever or shock.

“There was a lot of trash floating about, and among it we noticed quite a number of jellyfish, as well as some Portuguese men-of-war,” Wang said, adding that he managed to scoop up 20 of the creatures within a 100m radius.

Wang suspects that there are more of them in nearby waters, adding that he gave the 20 men-of-war to the National Museum of Marine Science and Technology in Keelung.

The museum’s exhibit and educational division chief Chen Li-shu (陳麗淑) said Portuguese men-of-war are usually found in the northern Atlantic Gulf Stream or off the south coast of Africa.

However, it is not uncommon to see a few of them drifting in waters off the Badouzih (八斗子) area of Keelung after the annual Dragon Boat Festival, Chen said, adding that this year had brought more of the creatures to Taiwanese waters than usual.

Chen urged tourists and other beachgoers to take care, as the tentacles of the Portuguese man-of-war contain venom which can remain active for several days even if the tentacle has been severed or the organism had died.

Chen Hui-tsai (陳輝財), the head of the emergency room at the Department of Health Keelung Hospital, offered tips on how to treat stings by Portuguese men-of-war.

Chen Hui-tsai said that a common treatment for jellyfish stings, bathing the area with urine, does not work with Portuguese man-of-war stings and will only make the pain more intense — if you are stung, instead wash the affected area with salt water.

Victims should also use a rigid object — such as a credit card — to scrape the stinger from the skin and seek expert medical advice as soon as possible, the doctor said.